ALLEN PARK — Tony Scheffler suffered a concussion on Sunday, but the Lions tight end didn’t realize it until he started having symptoms on Tuesday.
This is not unusual for concussions. They don’t always manifest themselves immediately which makes them difficult to test for.
“Even Monday he wasn’t having headaches and some of those other symptoms that we see,’’ coach Jim Schwartz said. “When we came back to work on Tuesday, we saw it. We have seen that from other people in the past. Every one of them is different that’s why it’s so hard to diagnose.’’
Scheffler took a shoulder hit to his helmet from safety Jerron McMillan who was penalized for unnecessary roughness and fined $15,000 for it.
Running back Theo Riddick also suffered a concussion Sunday at Green Bay but his was immediately apparent and he was sent to a hospital there to be examined before flying home with the team.
“Anytime you get a concussion, whether it’s your first, third, you bounce back quickly or you don’t it’s always a concern,’’ Schwartz said.
Neither was at practice on Wednesday or Thursday.

Give Gandy a chance
Dylan Gandy was a little taken aback when reporters walked into the locker room on Thursday and most of them gathered around him, even though he was fully naked.
Offensive coordinator Scott LInehan had just told the media that Gandy, the back-up offensive lineman, had offered to help the wide receivers if Calvin Johnson doesn’t play. He thinks he has the hands to be of service.
Hands? What do his teammates think of his hands?
“Jealousy causes people to do certain things that they wouldn’t normally do so I don’t know what they would say,’’ Gandy said with his dead-pan sense of humor.
How often does he mention his availability to LInehan?
“All the time,’’ Gandy said.
Linehan’s response?
“What do you think he says?” Gandy asked.
He does occasionally line up as the sixth offensive lineman. It’s not out of the realm of possibility he could catch a pass, but don’t count it.

Ins and outs
Calvin Johnson (knee), Louis Delmas (knee) and Chris Houston (hamstring) returned to practice after sitting out on Wednesday. All were limited.
Safety Glover Quin (ankle) was also limited.
Out on Thursday were: Scheffler (concussion), Riddick (concussion), Ashlee Palmer (ankle) and Jason Fox (knee).
Nate Burleson, who broke his forearm on Sept. 24, was back for the second straight day running position drills using a tennis ball instead of a football.